This invention is concerned with a fastener-installing tool comprising presenting means (e.g. a nosepiece) for receiving an elongated fastener element (e.g. a blind-riveting assembly, weld stud) and holding it with one end exposed for presentation to a workpiece, the presenting means being mounted for axial reciprocation between fastener-receiving and fastener-installing positions, and delivery means by which fasteners are conveyed from a delivery end of a supply source to said presenting means when retracted to its fastener-receiving position.
The installation of fasteners, (e.g. blind-riveting assemblies and weld studs), especially fasteners such as those which have cylindrical shanks with radially projecting flanges, require to be presented to the workpiece by means, e.g. a nosepiece, which closely embraces the shank. It is often also desirable that such means surrounds the shank completely, or as completely as possible, especially if the means, as is the case with a nosepiece in blind riveting, is going to apply pressure to the flange of the fastener.
Fasteners can be fed to the presenting means of tools of the kind under consideration either from the front or from inside the tool, and automatic means of both types have been proposed. In the latter type, while external attachments near the presenting means such as might impair the maneuverability of the tool may be avoided, it follows that the presenting means itself must be openable to allow the flange of the fastener to pass through it, either before or after the installing operation, depending on the particular fastener and operation. A split nosepiece is commonly used in such circumstances, but has the disadvantages of complexity and susceptibility of becoming jammed against closing properly compared with a solid nosepiece such as can be used if the fastener is fed into it from the front.
A proposal for a front-feeding arrangement for blind-riveting tools is described in U.S. Pat. No. 4,059,981. In U.S. Pat. No. 4,065,952 there is shown a feeding unit inside the tool.
The foregoing proposals offer a variety of arrangements for the automatic front-feeding of blind-riveting assemblies. All are subject to limitation as to their suitability because of the space they occupy or require in operation, their cost or complexity, or their operational efficiency. Similar considerations applies to the front feeding of stud welding tools. It is accordingly an object of the present invention to provide a fastener-inserting tool of the kind referred to with improved means for the reloading of the presenting means from the front between a successive installing operation.